适用 docker 场景
Storage Driver: overlay2
Backing Filesystem: xfs
目的
防止某一容器无休止写入，导致docker持久化目录空间枯竭，进而导致docker无法正常运行
环境准备
- 测试机安装 docker
- 测试机添加数据盘，用于模拟 docker 持久化目录
初始化环境信息如下:
$ df -Th
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 7.8G 0 7.8G 0% /dev
tmpfs tmpfs 7.8G 0 7.8G 0% /dev/shm
tmpfs tmpfs 7.8G 8.9M 7.8G 1% /run
tmpfs tmpfs 7.8G 0 7.8G 0% /sys/fs/cgroup
/dev/mapper/centos-root xfs 49G 1.9G 48G 4% /
/dev/sda1 xfs 1014M 195M 820M 20% /boot
tmpfs tmpfs 1.6G 0 1.6G 0% /run/user/0
/dev/sdb1 xfs 100G 33M 100G 1% /xfs
$ cat /etc/docker/daemon.json
{
"registry-mirrors":[
"https://pee6w651.mirror.aliyuncs.com",
"https://docker.mirrors.ustc.edu.cn",
"http://hub-mirror.c.163.com"
],
"insecure-registries":["gcr.azk8s.cn","dockerhub.azk8s.cn","quay.azk8s.cn","5twf62k1.mirror.aliyuncs.com","registry.docker-cn.com","registry-1.docker.io"],
"max-concurrent-downloads":3,
"log-driver":"json-file",
"log-opts":{
"max-size":"100m",
"max-file":"1"
},
"max-concurrent-uploads":3,
"storage-driver":"overlay2",
"storage-opts": [
"overlay2.override_kernel_check=true"
],
"live-restore": true
}
docker 持久化目录文件系统类型必须为 xfs
调整docker持久化目录
- 修改 /etc/docker/daemon.json 文件内容，调整 docker 持久化目录为 xfs 分区下，调整后配置如下
$ cat /etc/docker/daemon.json
{
"registry-mirrors":[
"https://pee6w651.mirror.aliyuncs.com",
"https://docker.mirrors.ustc.edu.cn",
"http://hub-mirror.c.163.com"
],
"insecure-registries":["gcr.azk8s.cn","dockerhub.azk8s.cn","quay.azk8s.cn","5twf62k1.mirror.aliyuncs.com","registry.docker-cn.com","registry-1.docker.io"],
"max-concurrent-downloads":3,
"log-driver":"json-file",
"log-opts":{
"max-size":"100m",
"max-file":"1"
},
"data-root": "/xfs/docker",
"max-concurrent-uploads":3,
"storage-driver":"overlay2",
"storage-opts": [
"overlay2.override_kernel_check=true"
],
"live-restore": true
}
即以下配置内容
"data-root": "/xfs/docker",
- 重载配置以生效
$ systemctl daemon-reload
$ systemctl restart docker
- 启动测试容器，创建
40G文件
$ docker run -idt --name ddd alpine:latest
$ docker exec -it ddd sh
/ # dd if=/dev/zero of=test.file bs=1M count=40960
40960+0 records in
40960+0 records out
/ # du -sh test.file
40.0G test.file
- 查看容器磁盘使用量
$ docker system df -v |grep "alpine:latest"
a8c777259823 alpine:latest "/bin/sh" 0 42.9GB 27 minutes ago Up 27 minutes ddd
- 清理掉测试容器
$ docker rm -f ddd
- 修改 /etc/fstab 挂载参数，开启磁盘配额功能
否则配置容器存储限额后，启动会报如下异常
Jan 03 10:14:01 localhost dockerd[52920]: failed to start daemon: error initializing graphdriver: Storage option overlay2.size not supported. Filesystem does not support Project Quota: Filesystem does not support, or has not enabled quotas
修改前，挂载参数
$ mount |grep sdb1
/dev/sdb1 on /xfs type xfs (rw,relatime,attr2,inode64,noquota)
修改 /etc/fstab 内 /xfs 挂载点挂载参数，以开启磁盘配额功能
$ cat /etc/fstab|grep sdb1
/dev/sdb1 /xfs xfs defaults,usrquota,prjquota 0 0
刷新挂载信息
$ mount -av
/ : ignored
/boot : already mounted
/xfs : successfully mounted
此时挂载参数（已生效）
$ mount |grep sdb1
/dev/sdb1 on /xfs type xfs (rw,relatime,attr2,inode64,usrquota,prjquota)
- 配置 docker 容器存储配额为 20G
$ cat /etc/docker/daemon.json
{
"registry-mirrors":[
"https://pee6w651.mirror.aliyuncs.com",
"https://docker.mirrors.ustc.edu.cn",
"http://hub-mirror.c.163.com"
],
"insecure-registries":["gcr.azk8s.cn","dockerhub.azk8s.cn","quay.azk8s.cn","5twf62k1.mirror.aliyuncs.com","registry.docker-cn.com","registry-1.docker.io"],
"max-concurrent-downloads":3,
"log-driver":"json-file",
"log-opts":{
"max-size":"100m",
"max-file":"1"
},
"data-root": "/xfs/docker",
"max-concurrent-uploads":3,
"storage-driver":"overlay2",
"storage-opts": [
"overlay2.override_kernel_check=true",
"overlay2.size=20G"
],
"live-restore": true
}
即添加如下内容
"storage-opts": [
"overlay2.size=20G"
],
重载以生效
$ systemctl daemon-reload
$ systemctl restart docker
- 再次启动测试容器，创建 40G 文件
$ docker run -idt --name ddd alpine:latest
$ docker exec -it ddd sh
/ # dd if=/dev/zero of=test.file bs=1M count=40960
40960+0 records in
40960+0 records out
/ # du -sh test.file
20.0G test.file
通过添加容量配额后，当我们尝试创建 40G 文件，只能创建出 20G 大小的文件，即我们配置里所限制的大小。
上面结果表明容器配额已生效。
- 清理掉测试容器
$ docker rm -f ddd
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